Today it is common to utilise unicast point-to-point connections for delivery of mobile and stationary IPTV services via a channel, or a part of a channel. Unicast delivery always requires that the address of the end user at the end point is known, but once the address is known the conventional unicast delivery system offers a straightforward mechanism which is easy to apply for providing usage and service monitoring. Unicast services are easy to track, mainly because this type of service is normally authenticated, authorized and logged whenever an end user makes an attempt to access it.
From an IP network point of view, both broadcast and multicast delivery offers a more efficient way of delivery of services than unicast, basically due to a more efficient utilisation of the available network resources. Broadcast/multicast services are typically encrypted to ensure delivery only to those end users that are entitled to receive a respective service, i.e. end users having the correct decryption.
There are several standards available for this type of service delivery, which are based on a key exchange mechanism, for providing a reliable way of keeping control of the service distribution, and for assuring that only those end users that are entitled to a specific service will be able to access it.
Unlike unicast delivery, a broadcasted/multicast service is by definition transmitted from one end point, and potentially received at a plurality of end points. In many applications it is useful, both from a commercial, as well as from a technical perspective, to be able to determine to what extent a service is being consumed, and, optionally also to categorise the users of the service.
A problem with the broadcast/multicast delivery solutions which are offered today is, however, how to identify when a specific service provided by a service provider is requested by an end user, not to mention the difficulty to identify a specific end user, as an end user having requested a specific service.
For a broadcast/multicast operator gathering statistics as indicated above it would, however, be desirable to avoid to involve excessive point to point unicast links, which could mitigate the advantages of running the broadcast/multicast distribution.